Along with high integration in LSIs, circuit line widths in semiconductor devices are becoming increasingly fine year by year. To form a desired circuit pattern on a semiconductor device, a method is used in which a high-precision original drawing pattern (also referred to as a mask or as a reticle particularly when the original drawing pattern is used by a stepper or scanner) formed on quartz is reduced and transferred to a wafer by using a reduction projection exposure apparatus. A high-precision original drawing pattern is drawn by an electronic beam drawing apparatus and a so-called electronic beam lithography technology is used.
When electronic beam drawing is performed, the layout of a semiconductor integrated circuit is designed first and layout data (design data) is created. Then, the layout data is converted to drawing data and the converted drawing data is input to an electronic beam drawing apparatus. The electronic beam drawing apparatus performs drawing according to the drawing data.
In electronic beam drawing, there are various phenomena that cause dimension variations; for example, an influence radius in a proximity effect is about 10 μm, and an influence radius in a fogging effect and a loading effect is about several mm. To suppress dimension variations due to these effects, dose amount correction computation has been performed in real time in the interior of the drawing apparatus.
As a phenomenon that causes a dimension variation, a proximity effect specific to an EUV mask with a very short influence radius of about 300 nm to 400 nm is known. When dose amount correction computation is performed with this effect taken into consideration, it is necessary to perform mesh division for a drawing area in units of, for example, about 50 nm to 100 nm and perform computation for each small divided area, so processing time in correction computation becomes vast. Since it is difficult to perform this type of computation in the interior of a drawing apparatus in real time, it is preferable to calculate the amount of correction in the outside in advance and input created correction information to the drawing apparatus.
As for correction information in a map form, however, the amount of data is large, so data transfer could not be efficiently performed. In addition, when mesh division is performed for a graphic and each small divided graphic has information about the amount of dose, the amount of data is increased according to the number of divisions.